Reliable event broadcaster with multiplexing and bandwidth control functions

• US 8,149,771 B2
• Filed: 01/24/2007
• Issued: 04/03/2012
• Est. Priority Date: 01/31/2006
• Status: Active Grant

• Current Assignee: DIRECTV, LLC (AT&T, Inc.)
• Original Assignee: Roundbox, Inc. (AT&T, Inc.)
• Inventors: Khivesara, Amit, Liu, Xiaofeng, Mataga, Peter Andrew, Torkelson, Cary, Valloppillil, Vinod, Villanueva, Edgar
• Primary Examiner(s): Hu, Jinsong
• Assistant Examiner(s): Nealon, William
• Application Number:
  US11/626,707
• Publication Number:
  US 20070180119A1
• Time in Patent Office: 1,896 Days
• Field of Search: None
• US Class Current: 370/329
• CPC Class Codes: H04L 12/1881 with schedule organisation, e.g. priority, sequence management
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/2475 for supporting traffic characterised by the type of applications
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/741 Holding a request until resources become available
• CPC Class Codes: H04L 47/762 triggered by the network
• CPC Class Codes: H04L 47/803 Application aware
• CPC Class Codes: H04L 47/805 QOS or priority aware
• CPC Class Codes: H04L 47/806 Broadcast or multicast traffic
• CPC Class Codes: H04L 47/824 Applicable to portable or mobile terminals
• CPC Class Codes: H04L 47/828 Allocation of resources per group of connections, e.g. per group of users
• CPC Class Codes: H04L 47/83 based on usage prediction

Abstract

A system, apparatus, and method for transmitting data in a broadcast mode to multiple devices operating in a network. The invention enables the efficient utilization of bandwidth while providing a desired level of quality of service for the applications executing on the devices that utilize the broadcasted data. The invention utilizes a set of bandwidth constraints in combination with a set of heuristics and rules for the allocation and re-allocation of bandwidth among multiple applications in a manner that minimizes the impact on the quality of service metrics of importance to the affected applications when contention exists for the network resources. The present invention implements processes to cause the quality of service provided to each application to degrade smoothly, with certain priorities and guarantees being maintained. The present invention also provides event segmentation and reassembly functions for applications, and includes reliability mechanisms to increase the ability to provide data to client devices that have not been actively receiving for significant periods of time.

Claims

1. A method for distributing events associated with a datacast application, the method comprising:

receiving a registration of at least one application including a specification of a level of delivery quality of service corresponding to the application and a specification of a maximum priority level corresponding to the application, the maximum priority level selected from an ordered plurality of priority levels;

opening a plurality of event sessions requested by the application including associating each of the plurality of event sessions with one of a plurality of distinct session priority levels specified by the application, each of the specified plurality of distinct session priority levels being restricted so as not to exceed the maximum priority level specified for the application; and

for each of the plurality of event sessions, at least;

converting the level of the delivery quality of service to an expected bandwidth for the event session;

a bandwidth requirement;

allocating bandwidth to the event session based at least in part on the expected bandwidth for the event session and the associated session priority level for the event session;

receiving a publication of at least one event object associated with the event session;

responsive to receiving the publication of the at least one event object, generating a plurality of data packets corresponding to a segmentation of the event object, wherein the data packets are generated at a rate corresponding to the bandwidth allocated to the event session; and

requirement; and

transmitting the data packets of the event object to at least one client device over a broadcast or multicast communication network.

2. The method of claim 1, further comprising:

registering the application on the client device;

receiving a data stream including the data packets at the client device;

assembling the data packets, wherein the assembled data packets are used to reconstruct each event object; and

delivering each event object to the application executing on the client device.

3. The method of claim 2, wherein transmitting the data packets comprises transmitting the data packets more than once such that different client devices receive the data stream at different times and each client device acquires each event object.

4. The method of claim 2, wherein transmitting the data packets comprises retransmitting previously transmitted data packets that are used by the client device to acquire each event object.

5. The method of claim 1, further comprising:

reallocating bandwidth to a plurality of applications.

6. The method of claim 5, wherein the allocated bandwidth corresponds to a value equal to or greater than a minimum guaranteed bandwidth and equal to or less than a maximum usable bandwidth.

7. The method of claim 5, wherein an amount of the allocated bandwidth is dependent on a total available bandwidth for allocation and bandwidth requirements of other applications.

8. The method of claim 5, wherein an amount of the allocated bandwidth changes in response to publication of high priority event objects.

9. The method of claim 5, wherein the bandwidth reallocation occurs responsive to at least one of:

publication of a new event object by an application;

removal of an existing event object by an event scheduler;

registration of a new application;

deregistration of an existing application;

creation, destruction or modification of sessions by an application; and

modification of overall bandwidth configuration.

10. The method of claim 1, wherein application registration is prevented when available bandwidth cannot be allocated to satisfy the level of the delivery quality of service for all applications.

11. The method of claim 10, further comprising:

modifying the level of delivery quality of service; and

registering the application with the modified level of delivery quality of service.

12. The method of claim 1, wherein one of the data streams is identified by the application as a data object delivery session.

13. The method of claim 1, wherein one of the data streams is identified by the application as an event stream session.

14. The method of claim 1, wherein one of the data streams is identified by the application as a notification session.

15. The method of claim 1, wherein the level of delivery quality of service is determined based on at least one of:

data size for a session, event frequency, event size, event acquisition time and event delivery reliability.

16. The method of claim 1, further comprising:

calculating the expected bandwidth for the event session based at least in part on bandwidth at least one of;

event size, event frequency, event latency time, an error correction requirement, session priority, and a number of re-transmissions.

17. The method of claim 16, wherein the expected bandwidth for the event session is calculated at different levels of delivery quality of service and is further based at least in part on, at least one of:

an expected quality of service, a minimum guaranteed quality of service, and maximum usable quality of service or bandwidth.

18. The method of claim 16, wherein calculating the expected bandwidth for the event session bandwidth requirement comprises:

determining an amount of data to be transmitted to the client device using a product of the event size, the event frequency and the number of re-transmissions;

multiplying the determined amount of data by an error correction factor to generate a corrected amount of data; and

dividing the corrected amount of data by an event latency value to generate the expected bandwidth for the event session.

19. The method of claim 1, further comprising:

caching the event object on the client device.

20. The method of claim 19, wherein the event object is cached at a location that is monitored by the application executing on the client device.

21. A datacasting system for event broadcasting distribution of a plurality of applications, the system including a broadcast server comprising:

a register element for registering an application with a level of delivery quality of service corresponding to the application and a maximum priority level corresponding to the application, the maximum priority level selected from an ordered plurality of priority levels, the application configured at least to request that the broadcast server open a plurality of event sessions requested by the application and associate each of the plurality of event sessions with one of a plurality of distinct session priority levels specified by the application, the broadcast server limiting each of the specified plurality of distinct session priority levels to the maximum priority level specified for the application, and wherein, for each of the plurality of event sessions, the level of delivery quality of service is converted to an expected bandwidth for the event session;

a bandwidth allocation element for allocating bandwidth to the plurality of event sessions based at least in part on the expected bandwidths for the plurality of event sessions and the associated session priority levels for the plurality of event sessions;

a publication element for accepting publication of at least one event object associated with at least one of the plurality of event sessions;

a packet generator for generating a plurality of data packets corresponding to a segmentation the event object, wherein the data packets are generated at a rate corresponding to the bandwidth allocated to at least one of the plurality of event sessions with which the event object is associated; and

a network communication element for formatting the data packets for transmission over a communication network.